Slow write speed could be a card problem. SD Extreme III is a reasonable performance card, the Ducati and Extreme IV are faster but not to much.
Try formatting the card in the camera.
Also where did you buy this, local or from overseas/ebay?
If not local, then check on card's authenticity. There some a good info on eBay about counterfeit cards in the guide section. Two that might help are:
http://reviews.ebay.com.au/How-to-te...00000001287720
http://reviews.ebay.com.au/FAKE-SanD...00000001254852
MY15 Discovery 4 SE SDV6
Past: 97 D1 Tdi, 03 D2a Td5, 08 Kimberley Kamper, 08 Defender 110 TDCi, 99 Defender 110 300Tdi[/SIZE]
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